A low-pressure carbonate reservoir gas well temporary plugging workover fluid and its preparation and application method

Abstract

A low-pressure carbonate reservoir gas well temporary plugging and workover fluid and its preparation and application method. The other plug is a water-based anti-swelling inhibitor plug, which is mainly used to further reduce the damage caused by a small amount of workover fluid entering the reservoir due to micro-leakage. harm. The invention has the characteristics of small leakage, small reservoir damage, strong pressure bearing capacity and water locking capacity, good universality, non-toxic, harmless, convenient construction, easy flowback, safety and environmental protection, and the like. It is mainly used for temporary plugging and killing of carbonate reservoirs during well workover, especially suitable for workover operations of gas wells in low-pressure carbonate reservoirs with pipe strings and packers, so as to reduce the damage of workover fluid to the formation.

Description

technical field [0001] The invention relates to the technical field of gas well workover, in particular to a temporary plugging and workover fluid for gas wells in low-pressure carbonate rock reservoirs and its preparation and application methods. Background technique [0002] Well workover is a work to restore normal production of oil and gas wells or increase production capacity to eliminate faults and improve wellbore conditions. The working fluid used in the workover operation is called the workover fluid. The workover fluid can ensure the safety of construction operations and prevent the workover fluid from leaking into the formation, thereby protecting the reservoir. [0003] At present, in the workover process of low-pressure gas fields at home and abroad, clay-free water-based workover fluids are generally used. There are roughly three types of workover fluids: clay-free clean brine workover fluids, low-solids-free Clay phase workover fluid, other types such as foam...

AI Technical Summary

Problems solved by technology

The disadvantage is that the workover operation time is long, and the contact time between the formation and the fluid is long, especially for low-porosity and low-permeability gas reservoirs, the degree of water lock damage will still be serious

[0005] Low solids and clay-free workover fluids can quickly form plugs in holes or fractures and control the loss of workover fluids. The disadvantage is that the solid phase particle invasion during the workover process will easily cause reservoir pore throat blockage, making it difficult to flow back , especially for low-permeability gas layers, it is difficult to remove plugging, and it is easy to cause damage to the reservoir

It can be seen that for the current gas wells in low-pressure carbonate reservoirs containing single or multiple packers, it is currently impossible to achieve temporary plugging and workover. Temporary plugging and workover fluid suitable for this type of tubing string with a packer in low-pressure carbonate reservoir gas wells and its application method

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